Language learning in the first months of life can be subconsciously retained even when no conscious knowledge of the early experience remains. The subconscious knowledge can then be tapped to speed up re-learning the sounds of the lost tongue, even including how to pronounce them. These are the conclusions of a study of international adoptees by Jiyoun Choi of Hanyang University, chief investigator Anne Cutler from the ARC Centre of Excellence for the Dynamics of Language and Mirjam Broersma of the Max Planck Institute at Radboud University. A paper describing their results has just been published in Royal Society Open Science.

For people adopted internationally the news is very good, especially as many of them try to reconnect with the people and culture of their birth countries. [From Adoptees advantaged by birth language memory, ARC Centre of Excellence for the Dynamics of Language]

Transcript

Robyn Williams: Imagine you were born in Korea. You heard, as a baby, Koreans talking. Then, while still very young, you were adopted and taken to Holland. Now, many years later, what are the chances that you could learn Korean even though you have forgotten everything about being there? This was the basis of a paper published by the Royal Society on work at Western Sydney University's Centre of Excellence, led by Professor Anne Cutler. It says lots about how cute babies can be listening and learning.

Let's start at the beginning with the baby in the womb. Let's imagine it is, say, six months, and it's lying there…

Anne Cutler: It's a good point, because by the third trimester of pregnancy we know that the auditory system is basically developed and it's from that point, six months in the womb, that they start being able to perceive auditory signals from outside the womb.

Robyn Williams: Auditory signals. Now, if I'm listening to a foreign language, I can hardly tell what is a word and what's just a continuing running noise. How is the baby, do you imagine, able to discriminate anything at that age?

Anne Cutler: Well, they are not discriminating very much, but you'd be surprised what can be heard in the womb. For instance, the thing that babies pick up on about the sound structure of language is that there are basically two kinds of sounds. There are continuous ones (vowels), and there are ones in between them (consonants), and that they can actually pick up even in the womb. So they are born with that knowledge but they weren't given it by their genes, they were given it by listening in the last trimester of pregnancy.

Robyn Williams: How do you know that?

Anne Cutler: We know that that's one of the earliest things that you can show in babies' awareness because within a few days of birth they can tell the difference between natural sounds, that is sequences of consonants and vowels (syllables), and the same kind of length of sounds, that is a sequence of three different sounds but it doesn't make up a syllable, so [pssst], you know. And they don't like listening to those ones but they do like listening to the real syllables like 'but'. We also know from studies that you can hear that difference in the womb because recordings have been made inside the womb not of a human but of another animal with exactly the same sort of distance between the head of the fetus and the outside world, namely the sheep. And so there's wonderful work on fetal sheep that has delivered us excellent recordings of exactly what you can hear in the womb, and you can hear the difference between vowels and consonants very easily.

Robyn Williams: Now, moving towards your paper which has just been published, about being able to discriminate between languages, what's that all about?

Anne Cutler: These adults that we tested were in their 30s, but when they were little babies they were adopted from a different country, namely Korea. And so they had been exposed to Korean. They would have heard as much as any baby hears at that age. If you ask them if they know any Korean they say, 'No, I've forgotten everything.' And if you ask them some simple words that babies at age one generally know, like 'mummy' or 'dirty' or 'bottle', they know nothing. You ask them the word geegee for instance, and say, does that mean a cookie? 'Ooh a geegee, look!' Or does it mean a hug? 'Let's have a geegee, wouldn't that be nice!' Or does it mean dirty, filthy, like, 'Ugh, put it down, geegee!' So what do you think?

Robyn Williams: I think it's a hug.

Anne Cutler: Wrong, it's dirty. But there you are, that's baby talk in Korean. And they were just a chance, you ask them that, they don't know anything, they just say, 'How can I remember?' So they don't know the language. But then you ask them to learn some of the sounds. Korean is very interesting because it has a consonant difference which we don't have in English. We have the difference between [tuh] and [duh], but they don't have that difference in Korean, they have three different kinds of [tuh], and that's the hardest kind of thing that you can learn, is when your language has one sound and the other language that you're learning has two or three sounds in the same space…just think [ruh] and [luh] for Asian learners of English, you know, that's one sound for them, two sounds for us, well this is three sounds in Korean compared with one sound for us.

So you put them in the experiment and you are going to learn this three-way distinction. And so along with them, and this is the largest group of adoptees that has ever been tested, and along with them we had a very large group of controls, and they were all matched exactly in education and background and so on. You put them in this experiment and everybody learns something about this very difficult distinction, they all learn. But the adoptees, they learn so fast, they just take off flying. It's like they've learnt significantly faster. So that was fine, just to identify them.

But then we also asked them to imitate the production. This is where it gets really interesting because they had to actually imitate what they were hearing. And then we recorded it all and we got some native Koreans to record the same, and then we sent it all to Korea and had unwitting participants in a psychology experiment, undergraduates, just rate them, how good is this syllable. And so they rate them, and of course the Koreans got perfect ratings, that's very good. But the adoptees wildly significantly outperformed the control subjects, their siblings.

And so how does this come about? It can only be that they have retained some knowledge. Now, what's the nature of this knowledge? Well, this is where our experimental design got very, very interesting because we had two groups of adoptees, and this was just something that actually was very easy to do in that population of adoptees at that time because there were kind of two waves of adoption. So we had roughly half of our participants, and from the second wave, and they were adopted between one and a half years and a couple of years of age, and then we had from the second wave the other half of our participants, and they were all adopted under six months of age.

Now, that's very interesting because in the world of language acquisition we know that there is something very important happening in the second half of the first year of life. You start to learn words, and when you can start to learn words you start to put them together with the sounds that you've been exposed to and saying, oh, okay, at the end of the first year of life, so from nine, ten months on you find infants in experiments responding basically like adults. They are very, very good at discriminating the sounds in their native language, but they ignore discriminations that don't occur in the native language. So you have Japanese infants of 10 months, they ignore [ruh, luh] distinctions, just like adults do. At six months of age babies can do everything. Japanese infants can distinguish between [ruh] and [luh] perfectly well, they just have to…once they've got words, they have to learn to ignore that.

Now, the interesting thing that ever since these results were found it has been kind of over-interpreted to say that before six months babies don't have any knowledge of phonology, they don't have any abstract rules and ideas about how the input they are getting is actually made up. But that can't be true, that cannot be true given our data because the babies who were adopted before six months behaved just in the same way as the babies who were older when they were adopted. That is to say, the adults who were adopted as babies younger than six months and the adults who were adopted as babies over one and a half years of age did not differ in their performance. Both groups more rapidly learned to tell the sounds apart, and most importantly they were significantly better at actually speaking the sounds.

Robyn Williams: So from birth they are beginning to store what you say is a kind of structure of language knowledge.

Anne Cutler: Correct, that's absolutely right, it's abstract knowledge about the phonological structure of the language. In this case, if you have a sound that is made with your tongue against your palate, [tuh], before a vowel you can have three kinds of that sound. And, what's more, when we were doing the testing, so the knowledge that they had was abstract of the kind you can have different kinds of ways of saying voiceless sounds before a vowel.

Robyn Williams: So this is a matter of perception, and of course it's way before they manage to speak themselves and their mouths are organised. And so it makes one a bit nervous, because tiny babies, you just assume they are blobs and they are not aware of anything much, and you are saying the opposite.

Anne Cutler: I am saying the opposite, I'm saying they are really working very, very hard at language. Actually when they start babbling, which is from about six months, within about two months you can tell what language they are babbling, or at least a mother can. So at six months everybody is babbling, they are babbling all sorts of sounds, but by about eight months, a mother can tell whether that baby is learning the same language as her own baby. And by 10 months everybody can tell. You can tell that baby is not learning English, that baby is doing pharyngal sounds, they are not learning English, and so on.

Robyn Williams: So what does this tell you about Noam Chomsky's idea that the brain is kind of preformed to be receptive to language, which seemed to go out of fashion a little bit, you know, Tom Wolfe's new novel being hyper-critical. So how does Chomsky stand up these days in 2017?

Anne Cutler: Chomsky still stands up very well. The whole field of psycholinguistics in a sense was founded by insights of Chomsky that language was actually a psychological phenomenon. It's something that the brain is particularly well adapted to, or language is adapted to the brain, you can have it either way. But the point is there is a natural match there. There's a lot of abstract structure that infants start picking up as soon as they can. The syntax of course is going to wait until you've got some vocabulary which starts in the second half of the first year of life, you start learning words. But even then…Jean Berko Gleason has shown us way back in the middle of the last century that very early on in the Chomskian revolution that the knowledge that children acquire the syntax of words very early on, they understand the rules, that is the abstract knowledge that drives how it works.

Robyn Williams: It's amazing, isn't it. What, finally, is the main message that results from the discovery you've made and the paper you've published?

Anne Cutler: You know what, the first author of this paper who did this work as her PhD…isn't it wonderful, to do something so amazing…what she says is talk to your baby. She says just talk, talk, talk all the time to your baby because your baby is picking up so much useful knowledge.

Robyn Williams: From the moment the baby is born?

Anne Cutler: Even before, three months before. Because before that they can perceive maybe warmth and affect, three months before birth they are already starting to be able to perceive something about the structure of sound.

Robyn Williams: Professor Anne Cutler, Centre of Excellence for the Dynamics of Language. And so to her inspiration in Boston, Professor Jean Berko Gleason.